T2 L5: Autonomic pathways

Question 1

What is the main autonomic centre?

Answer 1

Hypothalamus

Question 2

What do descending fibres innervate in the brainstem?

Answer 2

The parasympathetic cranial nerve nuclei and critical autonomic centres in the ventrolateral medulla

Question 3

What do descending fibres innervate in the spinal cord?

Answer 3

sympathetic and parasympathetic preganglionic neurones in the lateral horns

Question 4

What structures make up the limbic system?

Answer 4

The amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus

Question 5

What is the limbic system for?

Answer 5

Responsible for involuntary responses like emotions, blushing, and pallor

Question 6

Where do the sympathetic components of the autonomic NS originate from?

Answer 6

From the thoracic spinal cord and L1 and L2 (T1-L2)

Question 7

Where do the parasympathetic components of the autonomic NS originate from?

Answer 7

The brainstem and S2,S3, and S4 of the spinal cord

Question 8

What type of autonomic circuit does not form a disynaptic pathway?

Answer 8

Sympathetic supply to the adrenal medulla

Question 9

What is the main neurotransmitter found in autonomic ganglia?

Answer 9

Acetylcholine

Question 10

What type of receptor does ACh bind to?

Answer 10

Nicotinic

Question 11

How does ACh work to depolarise neurones?

Answer 11

Through ionotropic ligand-gated binding. It’s a fast process where ACh binds and opens the pore which depolarises the neuron

Question 12

What is the main neurotransmitter in postganglionic sympathetic neurones?

Answer 12

Noradrenaline

Question 13

What is the only area in the body that uses ACh in it’s sympathetic neurones?

Answer 13

Sweat glands

Question 14

How does noradrenaline depolarise neurones?

Answer 14

Through metabotropic G-protein coupled slow depolarisation

Question 15

Where are alpha-1 receptors found?

Answer 15

On blood vessels

Question 16

Where are beta-1 receptors found?

Answer 16

On the heart

Question 17

Where are beta-2 receptors found?

Answer 17

On the bronchi of the lungs

Question 18

What is the main neurotransmitter within the adrenal medulla?

Answer 18

ACh

Question 19

On which cells in the adrenal medulla are nicotinic receptors found?

Answer 19

Chromaffin cells

Question 20

What is atropine used for?

Answer 20

Treat bradycardia, dilate pupils, reduce glandular secretions….

Question 21

Which is faster, Metabotropic G-protein coupled release or Ionotropic ligand-gated release?

Answer 21

Ionotropic ligand-gated release

Question 22

What effect does sympathetic NS have abdomino-pelvic viscera?

Answer 22

Inhibits peristalsis and stimulates glucagon

Question 23

Through which structure do sympathetic preganglionic fibres enter the sympathetic trunk?

Answer 23

Through the white rami communicantes

Question 24

What are splanchnic nerves?

Answer 24

They don’t synapse in the sympathetic trunk

Question 25

What is the ratio of preganglionic neurones to postganglionic neurones?

Answer 25

1:20

Question 26

What are the 2 ways that neurones can leave the sympathetic trunk?

Answer 26

Through the grey rami communicantes back into spinal nerves (periphery) or they can leave via the medial plexus (viscera)

Question 27

Which parts of the body does cervical ganglia supply?

Answer 27

The head, upper limbs, and the heart

Question 28

What are the 3 divisions of cervical ganglia?

Answer 28

Super, middle, and inferior

Question 29

Where is the stellate ganglion?

Answer 29

It's fused to the inferior cervical and first thoracic ganglia

Question 30

What is the clinical significance of the stellate ganglia in terms of pain?

Answer 30

Blocking it is treatment for chronic pain

Question 31

How do postganglionic sympathetic fibres get to the heart?

Answer 31

They piggyback along the common carotid artery towards the heart

Question 32

How do postganglionic sympathetic fibres get to the head?

Answer 32

They piggyback up the internal/external carotid arteries towards the head

Question 33

What does the internal carotid plexus supply?

Answer 33

The eyes (dilates pupils and raises eyelids) and the lacrimal gland (inhibits secretions)

Question 34

What does the external carotid plexus supply?

Answer 34

The submandibular and parotid gland (inhibits secretions)

Question 35

What causes Horners syndrome and what are the signs?

Answer 35

It's caused by a disruption of sympathetic supply to the head and includes signs like miosis, ptosis, and anhidrosis

Question 36

What does Miosis mean?

Answer 36

Excessive constriction of the pupil

Question 37

What does Ptosis mean?

Answer 37

Drooping of the eyelid

Question 38

What does Anhidrosis mean?

Answer 38

Lack of sweating

Question 39

What can cause Horner's syndrome?

Answer 39

Lesions within the brainstem/cervical spinal cord Eg. with Multiple sclerosis

Question 40

What parts of the body do the thoracic ganglia supply?

Answer 40

Thorax, heart, lungs, and abdominal viscera

Question 41

What are the 3 divisions of thoracic splanchnic nerves?

Answer 41

Greater, lesser, and least

Question 42

What do the lumbar ganglia supply?

Answer 42

The abdominal viscera and lower limbs

Question 43

What does sacral ganglia supply?

Answer 43

The pelvis and lower limbs

Question 44

How do preganglionic lumbar sympathetic fibres exit?

Answer 44

Lumbar splanchnic nerves go to abdomen and synapse in the prevertebral ganglia

Question 45

Where in the body does parasympathetic nervous supply have an effect of blood vessels?

Answer 45

In male erectile tissue

Question 46

What nucleus does the oculomotor nerve (CN3) originate from?

Answer 46

The Edinger-Westphal nucleus in the midbrain

Question 47

What nucleus does the facial nerve (CN7) originate from?

Answer 47

The superior salivatory nucleus in the pons

Question 48

What nucleus does the Glossopharyngeal nerve (CN9) originate from?

Answer 48

The inferior salivatary nucleus found in the pons

Question 49

What nucleus does the Vagus nerve (CN10) originate from?

Answer 49

From the nuclues ambiguous and the dorsal motor nucleus in the medulla

Question 50

How do cranial parasympathetic preganglionic axons get into the cranium?

Answer 50

They pass through cranial nerves to ganglia

Question 51

Which ganglia provides information to the lacrimal gland?

Answer 51

The Pterygopalatine ganglia

Question 52

Which ganglia provides information to the parotid gland?

Answer 52

The Otic ganglion

Question 53

Which ganglion provides information for the submandibular gland?

Answer 53

The Submandibular ganglion

Question 54

Which ganglion provides information for the sphincter pupillae to contract pupils?

Answer 54

The Ciliary ganglion

Question 55

What organs does the vagus nerve pass on?

Answer 55

The heart, lungs, and abdominal viscera

Question 56

What functions do sacral parasympathetic nerves provide?

Answer 56

- Contraction of the bladder wall for urination and inhibition of the bladder sphincter - Inhibition of the rectal sphincter to allow for defecation - vasodilation in erectile tissues

Question 57

What effect does parasympathetic nervous supply have on male erectile tissues?

Answer 57

Erection

Question 58

What effect does sympathetic nervous supply have on male erectile tissues?

Answer 58

Ejaculation

Question 59

What are the 2 complexes in the enteric nervous system?

Answer 59

Auerbach's and Meissner's

Question 60

Where is the Auerbach's plexus and what does it do?

Answer 60

Found between the longitudinal and circular layer of muscle in the intestines. It regulates muscle contraction

Question 61

Where is the Meissner's plexus and what does it do?

Answer 61

Found between the circular muscle and mucosa layer. It regulates glandular contraction

Question 62

Which type of nervous system can be described as truly autonomic and why?

Answer 62

The enteric nervous system because you could remove it and it would still contract and secrete

Question 63

What do afferent pathways of the autonomic nervous system do?

Answer 63

They convey sensory information to autonomic centres via dorsal roots into the spinal cord and via CN9 and CN10 into the brainstem